Stationary pocket feeder apparatus for digester



March 11; 1969 E. J. JUSTUS 3,432,332

STATIONARY POCKET FEEDER APPARATUS FOR DIGESTER Filed ma 17, 1965 Sheet 2 of s Al? 1/0001? fl/VD 67/0 6 ab INVENTOR.

Y AT ORL'VEYS March 11, 1969 J s-rus 3,432,382

STATIONARY POCKET FEEDER APPARATUS FOR DIGESTER Filed May 17, 1965 Sheet 3 of 5 F 5 J 52b 34a 42b 3% L 4419 m f 6 55 g Era 32b 50b INVENTOR.

I 3 Y ATTORNEYS March 11, 1969 a. J. JUSTUS 3,432,332

STATIONARY POCKET FEEDER APPARATUS FOR DIGESTER Filed May 17, 1965 Sheet I N VEN TOR.

g 8 Z@ar J M apfldf ATFORNEYS March 11, 1969 E. J. JUSTUS 3,432,382

STATIONARY POCKET FEEDER APPARATUS FOR DIGESTER Sheet 5 of 5 Filed May 17, 1965 70 75 firm/00% 41/000? km A 6:9 INVENTOR.

M w Y fiTORNEYS United States Patent 7 Claims ABSTRACT OF THE DISCLOSURE Apparatus including a pair of valves for transferring wood chips from a first to a second liquor in a continuous pulping process. A screen is disposed either on the stationary valve housing or on the movable valve member of one of the valves to remove the chips from the first liquor and to transfer the same to the second liquor as the valves are changed from one position to another.

This invention relates generally to pulp and papermaking apparatus and more particularly to apparatus for transferring and feeding wood chips during a continuous pulping process.

Advances have been made in the development of continuous pulping processes and there are now a number of soundly developed systems for continuous pulping, particularly of the chemical and semi-chemical types. Continuous pulping can afford many advantages over a batch operation, among which are reduced time requirements, a more uniform product, utilization of better control methods, greater flexibility and the ability to use lower liquor ratios.

Continuous pulping processes are often complicated, however, and have presented problems of mechanical design. For example, in some operations such as in feeding wood chips to the digesters or in transferring the wood chips from one digester to another the chips may desirably be first carried in one fluid medium such as a first liquor and then transferred to another fluid medium such as a second liquor which might be at a different pressure, temperature, etc. than the first liquor.

The present invention is addressed to such problems and provides means not only for effecting such transfer but for accomplishing the transfer continuously as required in feeding wood chips in a continuous pulping process.

The feeding or transfer appartus of the present invention is simple in design, relatively inexpensive in manufacture, provides a high transfer or feeding capacity, is easy to operate, can be controlled automatically, is rugged in construction and can serve a long, useful life.

It is, therefore, an object of the present invention to provide means for transferring wood chips from a first liquor to a second liquor, the two liquors having different conditions of pressure or temperature or the like.

Another object of the invention is to provide a transfer mechanism for solids such as wood chips which has a stationary collection chamber formed therein whereby a number of operations can be performed on the solids while they are contained in the chamber.

Another object of the invention is to provide a digesting system for a continuous pulping process including means for continuously delivering Wood chips to the digester for processing.

Another object of the invention is to provide a transfer mechanism for transferring wood chips from a first liquor to a second liquor and including a plurality of flow valves through which the two liquors alternately flow either in one direction or in opposite directions.

Still another object of the invention is to provide a 3,432,382 Patented Mar. 11, 1969 transfer mechanism which is simple in design, relatively inexpensive in maufacture, provides .a high transfer capacity, is easy to operate, can be controlled automatically, is rugged in construction and can serve a long, useful life.

Many other features, advantages and additional objects of the present invention will become manifest to those versed in the art upon making reference to the detailed description which follows and the accompanying sheets of drawings, in which perferred structural embodiments incorporating the principles of the present invention are shown by way of illustrative example only.

In the drawings FIGURE 1 is a schematic plumbing diagram of a continuous digesting system incorporating the principles of the present invention;

FIGURE 2 is a plan view of one embodiment of a feeder or transfer unit of the present invention with certain parts broken away for clarity;

FIGURE 3 is an enlarged sectional View of one of the valves of the embodiment of the feeder unit illustrated in FIGURE 2 and includes a screen member mounted on the valve housing;

FIGURE 4 is similar to FIGURE 3 but shows the screen mounted on a movable valve member of the valve;

FIGURE 5 is a sectional view of another form of a valve which can be advantageously utilized in that embodiment of the feeder unit shown in FIGURE 2 and includes a screen formed in an immovable liner of the valve;

FIGURE 6 is similar to FIGURE 5 but includes a screen mounted on the movable valve member;

FIGURE 7 is a sectional view taken substantially along lines VII-VII of FIGURE 5;

FIGURE 8 is a plan view of another embodiment of a feeder or transfer unit constructed in accordance with the principles of the present invention;

FIGURE 9 is an enlarged sectional view of one of the valves included in the embodiment of the invention shown in FIGURE 8; and

FIGURE 10 is a sectional view taken substantially along line XX of FIGURE 9.

As shown in the drawings Although the principles of the present invention are applicable in any system wherein solids are to be transferred from one fluid medium to another, a particularly useful application is made to a pulping process in the manufacture of stock for making paper products wherein wood chips are treated mechanically and/ or chemically at a plurality of treatment stations or zones and may be transferred from one treatment zone to another in one or more liquor mediums, as will be understood by those skilled in the art.

The present invention is also particularly useful where the transfer of the solids is essentially a continuous process. For example, generally in a pulping process the wood chips are subjected to certain treatment before entering the digesters. In a batch operation, the chips are moved periodically from one treatment station or zone to another, and then delivered to the digester or digesters in a slug or batch. As noted hereinabove, a batch operation is not generally as desirable as a continuous process wherein the chips are continuously moved through the various treatment zones and into and through the digesters.

A continuous pulping process, however, raises certain problems, not the least of which involves the continuous transfer of the chips from one fluid medium to another through the various treatment zones and into the digesters.

The present invention provides improved means for effecting such transfer and for continuously moving the chips through the various treatment zones and into the digesters. Referring to FIGURE 1, a typical digester, as will be understood by those skilled in the art, is indicated generally at reference numeral 10. The digester generally receives the chips after they have been worked on in other treatment zones.

For example, in some pulping processes the chips are delivered from a chipper or a grinder in a first liquor medium to a first treatment zone. The particular liquor utilized is generally necessary for the proper treatment of the chips and after this phase of the process is completed the chips may be moved to a second treatment zone. The second treatment may require a second liquor, which may be chemically different from the first liquor or may differ only in temperature or pressure. In any event, it may not be the same liquor or may not be maintained under the same conditions ts the first liquor, and therefore the chips are transferred from the first to the second liquor. In so doing the two treatment zones should remain isolated from one another so that a higher pressure or temperature of the liquor of one will not be reduced to that of the order.

In FIGURE 1 it will be assumed that the treatment involved in the digester requires a high pressure liquor and that the next preceding treatment station utilizes a liquor similar to the liquor used in the digester process, but maintained at a lower pressure. It will be understood, however, that the difference between the two liquors could be temperature rather than pressure, or temperature and pressure, or the two liquors could differ chemically. However, for one or more of these reasons it is assumed that it is desirable to keep the two liquors separated, or at least substantially so.

Assume that reference numeral 11 denotes a conduit for conveying a flow of low pressure liquor having wood chips suspended therein from a treatment zone which next precedes the digester 10 in a pulping process. Assume further that the digester 10 utilizes a high pressure liquor which is conveyed by a conduit 12 and which flows in the direction indicated from a source thereof. The wood chips being carried in the low pressure liquor in conduit 11 are to be transferred to the high pressure liquor flowing in conduit 12, and for that purpose the respective conduits are connected to a feeder or transfer unit indicated generally at 13 which is constructed in accordance with the prniciples of the present invention.

Reference numeral 14 denotes a conduit carrying the low pressure liquor after it has passed through the feeder unit 13 and after the wood chips have been removed therefrom and transferred to the high pressure liquor. Reference numeral 16 denotes a conduit carrying the high pressure liquor after it has passed through the feeder 13 and after the chips have been transferred thereto, and this conduit is connected to the digester 10 for feeding the digester with a supply of treated chips.

Referring to the enlarged view of FIGURE 2, the transfer unit 13 comprises generally a pair of branches 17 and 17a which are disposed substantially symmetrically about a line drawn between these two branches, or along the longitudinal centerline of the transfer unit.

It will become apparent as the description proceeds that transfer unit 13 may comprise one of the two branches when utilized in a batch operation wherein the flow of chips to the digester is intermittent, but both of the branches are desirable in order to provide a continuous flow of high pressure liquor and wood chips to the digester in a continuous pulping process.

Branch 17 comprises a pair of similarly shaped valves 18 and 19 separated by a hollow tubularly shaped conduit or spacer 20. Valve 18 comprises a valve housing 21 having formed thereon three flanged conduit connections 22, 23 and 24 which are connected, respectively, to conduit 11, conduit 12 and to the spacer conduit 20.

The valve 18 also comprises a movable valve member 26 carried in the valve housing 21 for rotation about 'a central axis which, in the embodiment illustrated in FIG- URE 2, projects perpendicularly outwardly from the drawing.

The valve member 26 has a peripheral wall 27 which is shaped complementarily to an inner wall 28 of the valve housing 21 and is machined to provide a good sliding relation between the two parts but of sufiiciently close tolerance to preclude excessive leakage of liquor between the movable valve member 26 and the inner wall 28.

A pair of openings 29 and 30 are formed in the valve member 26 and are in fluid communication with one another through a flow passage 31 situated between the two openings. The passageway 31 can be described for purposes of orientation as extending generally symmetrically about a plane which is perpendicular to the axis of rotation of the valve member 26, that is, a plane parallel to the plane of the drawing.

Valve 19 is similar to valve 18 and comprises a valve housing 32 having formed thereon a flanged connection 33 which is attached to the spacer conduit 20, a connection 34 which is attached to conduit 14" and a connection 36 which is connected to conduit 16" which supplies high pressure liquor and wood chips to the digester 10 of FIGURE 1.

The valve 19 also includes a movable valve member 37 which is similar to previously described valve member 26 and is rotatably carried in the valve housing 32. A peripheral wall 38 thereof is shaped complementarily to an inner wall 39 of the valve housing and a pair of openings 40 and 41 are formed in the valve member and are connected by a flow passageway 42 formed similarly to the flow passage 31 of the valve 18.

In order to transfer the wood chips from the low pressure liquor to the high pressure liquor a screen member 43 is fixedly mounted on the inner wall 39 of the valve housing 32 to extend completely across the interior of the connector 34. An inner surface 44 of the screen is shaped complementarily to the inner Wall 39 of the valve housing to maintain a good sliding relation between the valve member and the valve housing and screen.

Conduits 11, 12, 14 and 16' which convey the low and high pressure liquors to and from the branch 17 have their counterparts in branch 17a and are indicated respectively at reference characters 11", 12", 14" and 16". The remaining portions of branch 17a are similar to their counterparts in branch 17 which are indicated by similar reference characters with sufiix 0 added, and a detailed description thereof will therefore be omitted.

In describing the operation of the transfer unit 13 it will be assumed that initially the various valve members are disposed in the positions thereof illustrated in FIG- URE 2. It will be further assumed that conduits 11' and 11" are connected by a header 11 (FIGURE 1) to a source of low pressure liquor and chips, such source comprising, for example, the treatment station next preceding the digester 10. It will further be assumed that conduit 12 is connected to a source of high pressure liquor and conduit 16 delivers high pressure liquor and chips to the next succeeding treatment station such as the digester 10.

Referring first of all to branch 17a it will be noted that with valves 18a and 19a in the positions shown the low pressure liquor and chips will flow through valve 18a, the spacer conduit 20a and the valve 19a. The wood chips that are carried by the low pressure liquor will impringe and collect on the screen 43a in the valve 19a so that only the low pressure liquor will flow outwardly through conduit 14".

After a given quantity or slug of low pressure liquor and chips have been supplied to the valve 18a, or after a flow has been maintained therethrough for a given period of time, and after a given quantity of chips have accumulated in the valve member 37a, and perhaps even in the spacer conduit 20a (in the event of which the spacer conduit serves as a collection chamber), ,valve members 26a and 37a are rotated simultaneously such that the flow passageway 31a communicates the high pressure liquor conduit 12" with the collection chamber" 20a, and the flow passageway 42a communicates the collection chamber 2011 with the high pressure liquor and chips conduit 16".

As the valve member 37a is rotated in the valve housing 32a to this second position of operation, the chips which have accumulated in the passageway 42a remain there, and the chips which are directly deposited on the screen 43a are scraped off the screen and remain in the passage 4201 as the valve member turns. Any accumulated chips in the collection chamber 20a will also remain there during rotation of the valve member 37a to its second operating position, whereupon the high pressure liquor enters the valve 18a and flushes the wood chips in the collection chamber 20a and in the passageway 42a out the conduit 16" to the digester 10.

If the positions of the valves 18gt(dce ksr.aff

If the positions of the valves 18a and 19m shown in FIGURE 2 are in what may be defined as a first operating position, the valves 18 and 19 are in what may be defined as the second operating position. All four of these valves may be turned simultaneously between their two operating positions, and as a consequence during such periods of time that branch 17a is accumulating or collecting wood chips therein, the branch 17 is supplying high pressure liquor and wood chips to the digester 10. After all of the valves have been turned to their other operating positions, the wood chips previously accumulated in branch 17a are flushed to the digester 10, and the wood chips carried by the low pressure liquor are accumulated in branch 17.

As a consequence, in a continuous pulping process the transfer unit 13 may be utilized to substantially continuously transfer the wood chips from the low to the high pressure liquor and to supply the high pressure liquor and Wood chips to the digester 10.

In the embodiment of FIGURE 2 wherein he screen members 43 and 43a are fixedly mounted on their respective valve housings, it will be appreciated that the source of high pressure liquor can be connected to conduits 16' and 16 as well as to conduits 1 2 and 12" as shown. In such event the flow of high pressure liquor through the branches 17 and 17a would be from the bottom of the drawing to the top instead of from the top of the drawing to the bottom as shown. The flow passageways 42 and 42a and the collection chambers 20 and 20a can be flushed of the wood chips regardless of the direction of flow of the high pressure liquor.

FIGURE 3 is illustrative of flow paths through the valve 19 when, for example, the flow of high pressure liquor is in a direction opposite to that shown in FIGURE 2. In the position of the valve shown in FIG- URE 3 low pressure liquor and chips enters the valve through connection 33 and the low pressure liquor is discharged from connection 34.

When the valve member 37 is rotated to its other position of operation wherein the flow passageway 42 communicates connectors 33 and 36, the high pressure liquor enters the valve through connection 36 to flush the Wood chips upwardly out of the valve through connection 33 through the collection chamber 20, and out of conduit 12 to the digester 10.

FIGURE 4 is illustrative of a modified form of the valve 19 wherein a screen member identified at reference numeral 50 is actually mounted on the movable valve member 37 rather than on the inner wall 39 of the valve housing 32. Once again the contour of the screen 50 shaped complementarily to the inner wall 39 of the valve housing 32. With this arrangement, however, it is neces sary that the high pressure liquor enter the valve 19 through the connection 36 rather than the connection 33 since the wood chips deposited on the screen 50 must be back washed from the screen.

Thus, where the valves 18 19, 18a and 19a are of the embodiment illustrated in FIGURE 3, the flow of high pressure liquor may be in the direction thereof indicated in FIGURE 2, or may be in the opposite direction. When the valves are of the embodiment shown in FIGURE 4, however, the flow of high pressure liquor must be in the direction shown in FIGURE 4 in order to wash the wood chips from the screen 50.

It will be understood that a suitable linkage mechanism as indicated diagrammatically at 51 in FIGURE 2 may be provided to effect simultaneous rotation of all four of the valves between their respective operating positions.

Another embodiment of a valve constructed in accordance with the invention is illustrated in FIGURES 5 and 7 wherein parts similar to those shown in FIGURE 3 are given like reference characters with the suffix b added.

In this embodiment the valve housing 32b is generally tubular or cylindrical in con-figuration. The moveable valve member 3712 is shaped complementarily thereto and comprises a cylindrical peripheral wall 38b and a pair of radially extending end walls 38b and 38b", and is adapted to rotate within the valve housing 32b about its longitudinal axis.

The flow passageway 42b extends generally symmetrically about a plane in which the axis of the valve member 37b resides (as opposed to the disposition of the flow passageway 42 of the valve 19 in FIGURE 3) and communicates an opening 55 formed in the radial end wall 38b and another opening 55 formed in cylindrical peripheral wall 38b.

Also as shown, a cylindrical sleeve or valve liner 52 is immovably interposed between the valve housing 32b and the movable valve member 37b and has formed therein a screen portion 44b dimensioned to cover the opening of connection 341; and an opening 52' dimensioned similarly to the opening of the connection 36b.

In this embodiment of the valve wherein the screen is fixed with respect to the movable valve member it will be appreciated that the high pressure liquor can enter through connection 33b (similarly to the flow of high pressure liquor through valve 19 of FIGURE 2) or through connection 36b (similarly to the fiow of high pressure liquor through the valve 19 of FIGURE 3).

The valve shown in FIGURE 6 is similar to that of FIGURE 5 except that in this embodiment a screen 5011 is mounted directly on the movable valve member 37b in a manner similar to the mounting of the screen 50 on the valve member 37 in FIGURE 4. In this embodiment, therefore, the high pressure liquor should enter through connection 36b in order to back flush the wood chips in the manner described hereinabove with respect to the embodiment of FIGURE 4.

Referring again to FIGURE 2, oneor more fluid connections as indicated at 5-4 and 56 may be formed on the spaced conduit or collection chamber 20 in order to circulate one or more fluid substances therethrough for providing additional treatment to the wood chips while they are housed within the chamber 20.

For example, the stationary pocket or chamber 20 may be provided with an inner wall 57 situated in radial spaced relation to an outer wall 58 to provide a jacket 59 therebetween. Steam may be circulated through the jacket 59 by means of the connections 54 and 56 in order to heat the chips before they are flushed by the high pressure liquor into the digester.

It will be appreciated that as a result of the provision of the stationary pocket or collection chamber 20 situated between the valves 18 and 19 an additional treatment Zone is provided for further treatment of the chips, which can be subjected to a variety of treatments while they are housed in the collection chamber.

Another embodiment of an overall transfer or feeder unit of the invention is shown in FIGURE 8 and is again indicated generally at reference numeral 13. In the illustration the direction of flow of both the low and high pressure liquors are represented as entering the unit from the lower portion thereof, as opposed to the direction of flow thereof represented in FIGURE 2. The embodiment of FIGURE 8 also comprises a pair of branches identified generally at reference numerals 60 and 60a which may be generally identical to one another, although for purposes of clarity and in order to illustrate various views of the plumbing circuitry and various cross-sections of the valves, branch 60a is shown as being rotated approximately 90 degrees with respect to branch 60.

Referring first of all to branch 60, a pair of valves 61 and 62 are interconnected by means of a stationary pocket or spacer conduit 63. Branch 60a has a pair of valves identified by reference numerals 61a and 62a which are similar to valves 61 and 62, but which, as noted above, are shown rotated 90 degrees with respect to valves 61 and 62.

In FIGURE 8, wherein parts of branch 60a which have identical counterparts in branch 60 are given identical reference characters, each of the valves 61 and 61a are illustrated as comprising a cylindrically shaped valve housing 64 which has formed thereon four conduit connections indicated at 66, 67, 68 and 69. Connections 66 and 67 are formed on mutually diametrically opposite portions of the valve housings and connections '68 and 69 are also formed on mutually diametrically opposite portions which are offset with respect to connections 66 and 67 by 90 The valves 61 and 61a also each comprise a cylindrical movable valve member 70 shaped complementarily to the valve housing 64 and rotatable about its longitudinal axis within the valve housing. A valve sleeve or liner 71 is situated within and is fixedly connected to each of the valve housings for receiving a corresponding valve member 70.

Each of the movable valve members 70 comprises a cylindrical peripheral wall 72 and a pair of longitudinally spaced radial end walls 73 and 74. An opening 76 is formed in the end wall 74 and a pair of diametrically opposed openings 77 and 78 are formed in the peripheral wall 72 whereby a generally Y shaped flow passageway 79 communicates these three openings with one another regardless of the position of the valve member 70 with respect to the housing 64.

Each of the immovable valve liners 71 has formed therein a pair of openings 80 and 81 in register with the open flow areas of connections 68 and 69. In addition the liners each have a pair of screen portions 82 and 83 covering respectively the open flow areas of connections 66 and 67 for connecting wood chips thereon.

It will be appreciated that with respect to valves 62 and 62a the liners 71 thereof have four circumferentially spaced openings formed therein which are similar to openings 80 and 81 and in register respectively with the open free flow areas of connections 66-69, since valves 62 and 62a do not perform any screening function. In other respects the valves 62 and 62a are identical to valves 61 and 61a.

In order to describe the operation of the transfer or feeder unit of FIGURE 8, it will be assumed that low pressure liquor and wood chips are being supplied through a pair of conduits 84 and 86, both of which may be connected to a common header as indicated diagramamtically at reference numeral 11. Both of these conduits branch off into two branch conduits as at 84', 84", 86' and 86". Branch conduits 84 and 84 are connected respectively to connections 66 and 67 of valve 62 and conduits 86' and 86" are connected respectively to connections 66 and 67 of valve 62a.

In the position of the valves shown, the low pressure liquor and chips will pass through passage 79 of the movable valve member 70 of valve 62, since the openings 77 and 78 of the valve member are in register with connections 66 and 67 thereof, whereas the low pressure liquor and chips will not flow through valve 6211, since the openings 77 and 78 thereof are not in alignment with connections 66 and 67, but instead with connections 68 and 69.

In valve 62 the low pressure liquor and chips pass through the opening 76 of the valve member 70 and into a stationary pocket or collection chamber 87 situated between valves 61 and 62, from whence it travels into the valve member 70 of valve member 71. The chips are collected on the inside surfaces of the screen portions 82 and 83 of the valve liner 71, while the low pressure liquor passes out of the connections 66 and 67 of valve 61 and into a pair of branch conduits 88 and 88" which connect to a single conduit 88. Conduits 88 and 88 have counterparts connected to connections 66 and 67 of valve 61a and both of these conduits connect to a single conduit 88. The pair of conduits 88, 88 may connect to a common header as indicated diagrammatically at 14.

Further assume that high pressure liquor is being supplied through a pair of conduits 89 and 90, both of which may be connected to a common header as indicated diagrammatically at reference numeral 12. Both of these conduits branch off into two branch conduits as at 89', 89", 90' and 90". Branch conduits 90' and 90" are connected respectively to connections 68 and 69 of valve 62a and conduits 89, and 89 are connected respectively to connections 68 and 69 of valve 62.

As wood chips from the low pressure liquor are being collected in valve 61 and collection chamber 87 of branch 66, chips previously collected in branch 60a are being flushed therefrom by the high pressure liquor. A pair of branch conduits 91 and 91" are connected to valve connections 68 and 69 of valve 61a and join together in a common conduit 91, which may connect to a common header indicated diagrammatically at 16 along with a counterpart conduit 92 which has a pair of branch conduits 92' and 92 connected to the valve connections 68 and 69 of valve 61.

After a predetermined time period, or after a given quantity of low pressure liquor and chips have been introduced to branch 60, all four of the valves are rotated 90 simultaneously, whereupon the chips collected in branch 60 are flushed therefrom by high pressure liquor, and low pressure liquor and chips are introduced to branch 60a.

As a consequence, and similarly to the operation of the feeder unit of FIGURE 2, while one branch is removing chips from the low pressure liquor the other branch is delivering high pressure liquor and chips, whereby the supply of high pressure liquor and chips can be maintained substantially constant.

In order to facilitate operation of the valves, the rotatable valve members 70 have corotatably connected thereto a plurality of shafts as at 93, which shafts serve to facilitate turning of the valve members. In addition a suitable linkage mechanism may interconnect all of the shafts 93 to provide simple and simultaneous rotation of the valve members between their various operating positions.

FIGURES 9 and 10 are illustrative of another form of valves 61 and 61a wherein a pair of screens are mounted on the movable valve member for rotation therewith rather than forming portions of the immovable valve liner as shown in FIGURE 8.

Thus, a pair of screens 94 and 96 which are contoured similarly to the contour of the inner wall of the valve housing 64 and to the peripheral wall 72 of the valve member 70 are fixedly mounted on the valve member to cover the openings 77 and 78. In this form of the valves it will be apparent that the high pressure liquor must wash through the valve member in a direction opposite to the direction of flow of the low pressure liquor and chips in order to remove the collected chips from the valve member.

Although minor modifications might be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably come within the scope of my contribution to the art.

I claim as my invention:

1. in a digester system:

a digester for receiving and digesting wood chips, first conduit means for supplying a first liquor having wood chips carried therein from a source thereof,

a second conduit means for supplying a second liquor from a source thereof, transfer means interconnecting said first and said second conduit means for transferring the wood chips from the first to the second liquor, third conduit means interconnecting said transfer means and said digester for delivering the second liquor and Wood chips to said digester, fourth conduit means connected to said transfer means for delivering said first liquor, after the wood chips have been transferred therefrom, back to the source,

said transfer means comprising a pair of interconnected pocket feeder valves each having a valve member movable between two operating positions, said first and said second conduit means each being connected to different ones of said valves, and said third and said fourth conduit means each being connected to different ones of said valves, said valve members in a first operating position communicating said first and said fourth conduit means and in the second operating position communicating said second and said third conduit means, and chip collecting means carried on the movable valve member of one of said valves and operative to remove chips from the first liquor when the valve members of said one valves is in said first operating position and to transfer the chips to the second liquor when the valve member of said one valve is in said second operating position. 2. In a digester system:

a digester for receiving and digesting wood chips, first conduit means for supplying a first liquor having wood chips carried therein from a source thereof, second conduit means for supplying a second liquor from a source thereof, transfer means interconnecting said first and said second conduit means for transferring the wood chips from the first to the second liquor, third conduit means interconnecting said transfer means and said digester for delivering the second liquor and wood chips to said digester, fourth conduit means connected to said transfer means for delivering said first liquor, after the wood chips have been transfered therefrom, back to the source thereof,

said transfer means comprising first and second interconnected pocket feeder valves each having a valve member movable between first and second operating positions, said first and said third conduit means being connected to said first valve and said second and said fourth conduit means being connected to said second valve, said valve members in one of their respective operating positions communicating said first and said fourth conduit means and in the other of their respective operating positions communicating said second and said third conduit means, and a screen member carried on the movable valve member of said second valve for removing chips from the first liquor when said valve members are in their first operating positions and for collecting the chips thereon,

the collected chips subsequently being flushed from said screen member by the second liquor when said valve members are in their second operating positions whereby the second liquor carries the chips to the digester. 3. In a digester system:

a digester for receiving and digesting wood chips,

a first conduit for supplying a first liquor having wood chips carried therein from a source thereof,

a second conduit for supplying a second liquor from a source thereof,

transfer means interconnecting said first and said second conduits for transferring the wood chips from the first to the second liquor,

a third conduit interconnecting said transfer means and said digester for delivering the second liquor and wood chips to said digester, and

a fourth conduit connected to said transfer means for delivering said first liquor, after the wood chips have been transferred therefrom, back to the source thereof,

said transfer means comprising first and second interconnected pocket feeder valves each having a valve housing and a valve member movable relative to said housing between two operating positions,

a fifth conduit interconnecting said valve housing,

said first and said third conduits being connected to said valve housing of said first valve and said second and said fourth conduits being connected to said valve housing of said second valve,

said valve members in one operating position communicating said first and said third conduits and in the other operating position communicating said second and said fourth conduits, and

a screen member fixedly mounted on said valve housing of said second valve for removing chips from the first liquor and for collecting the chips thereon when said valve members are in said one operating position thereof,

said valve member of said second valve being operative to remove the chips from said screen member in the other operating position thereof and to transfer the collected chips to the second liquor. 4. In a digester system:

a digester for receiving and digesting wood chips,

a first conduit for supplying a first liquor having wood chips carried therein from a source thereof,

a second conduit for supplying a second liquor from a source thereof,

a pair of transfer means each interconnecting said first conduit with said second conduit for transferring the wood chips from the first to the second liquor,

a third conduit interconnecting each of said transfer means and said digester for delivering the second liquor and wood chips to said digester,

a fourth conduit connected to each of said transfer means for delivering said first liquor, after the wood chips have been transferred therefrom, back to the source thereof,

each of said transfer means comprising a pair of interconnected pocket feeder valves each having a valve member movable between two operating positions,

each of said transfer means further having one of its valves connected to said first conduit and the other of its valves connected to said fourth conduit and also one of its valves connected to said second conduit and the other of its valves connected to said third conduit,

chip collecting means in each of said transfer means for removing the wood chips from the first liquor when the valves of the respective transfer means are in said one of their operating positions and for transferring the chips to the second liquor when the valves of the respective transfer means are in said other of their operating positions,

said valve members being arranged with respect to one another such that when the valve members of one of said transfer means are communicating said first and said fourth conduits the valve members of the other of said transfer means are communicating said second and said third conduits, and

means for simultaneously moving all of said valve members in both of said transfer means from one of their operating positions to the other whereby second liquor and wood chips are continuously delivered to said digester.

5. In a digester system:

a digester for receiving and digesting WOOd chips, first conduit means for supplying a first liquor having wood chips carried therein from a source thereof, second conduit means for supplying a second liquor from a source thereof, transfer means interconnecting said first and second conduit means for transferring the wood chips from the first to the second liquor, third conduit means interconnecting said transfer means and said digester for delivering the second liquor and wood chips to said digester, and fourth conduit means connected to said transfer means for delivering said first liquor, after the wood chips have been transferred therefrom, back to said source, said transfer means comprising a pair of pocket feeder valves connected to one another and having valve members movable between first and second operating positions,

said conduits being connected to said valves so that fluid communication is established only between said first and fourth conduits when said valves are in said first operating position and fluid communication is established only between said second and third conduit when said valves are in said second operating position,

said transfer means comprising means including said valve means for removing the wood chips from said first liquor when said valves are in said first operating position and for transferring the chips to the second liquor when said valves are in said second operating position. 6. In a digester system: a digester for receiving and digesting wood chips, first conduit means for supplying a first liquor having wood chips carried therein from a source thereof, second conduit means for supplying a second liquor from a source thereof,

transfer means interconnecting said first and second conduit means for transferring the wood chips from the first to the second liquor,

third conduit means interconnecting said transfer means and said digester for delivering the second liquor and wood chips to said digester,

fourth conduit means connected to said transfer means for delivering said first liquor, after the wood chips have been transferred therefrom, back to the source,

said transfer means comprising:

a pair of pocket feeder valves connected to one another and having valve members movable between two operating positions,

said first and second conduit means being connected to different ones of said valves and said third and fourth conduit means being connected to different ones of said valves,

said valve members in one of their operating positions communicating said first and fourth conduit means and in the other of their operating positions communicating said first and fourth conduit means and in the other of their operating positions communicating said second and third conduit means, and

screen means in said transfer means for removing chips from the first liquor when said valve members are in said one of their operating positions as the first liquor passes through said transfer means and for transferring the chips to the second liquor when said valve members are in said other of their operating positions.

7. In a digester system:

a digester for receiving and digesting wood chips,

a first conduit for supplying a first liquor having wood chips carried therein from a source thereof, a second conduit for supplying a second liquor from a source thereof,

transfer means interconnecting said first and second conduits for transferring the wood chips from the first to the second liquor,

a third conduit interconnecting said transfer means and said digester for delivering the second liquor and wood chips to said digester, and

a fourth conduit connected to said transfer means for delivering said first liquor, after the wood chips have been transferred therefrom, back to the source thereof,

said transfer means comprising:

a pair of interconnected pocket feeder valves each of which comprises a valve housing having a cylindrical bore formed therein and a complementarily shaped valve member carried in said bore for rotation about the axis thereof,

each of said valve members having a cylindrical peripheral wall and a radial end wall,

means forming an opening in said peripheral wall and an opening in said radial wall and a flow passageway communicating said openings in each of said valve members,

said first and second conduits being connected to different ones of said valves and said third and fourth conduits being connected to different ones of said valves,

said flow passageways in one of the operating positions of said valve members communicating said first and fourth conduits and in the other of said operating positions communicating said second and third conduits, and

means in said transfer means including said valve members for removing chips from said first liquor in the first operating position of said valve members and for transferring the chips to said second liquor in the second operating position of said valve members.

References Cited UNITED STATES PATENTS s. LEON BASHORE, Primary Examiner.

U.S. Cl.X.R. 

